Credit: The White House(WASHINGTON) -- President Obama spoke with Australian Prime Minister Tony Abbott on Sunday night regarding the situation surrounding the Malaysia Airlines plane that was shot down over eastern Ukraine last week.

Obama and Abbott agreed that the ongoing international investigation must be "prompt, full, unimpeded and transparent." Speaking for the second time in three days, the leaders also agreed that Russia has a responsibility to use its "extraordinary influence with the pro-Russian separatists who control the crash site" to inspire cooperation, a readout of the call said.

The two nations agreed to continue to coordinate closely during the course of the investigation. The Sunday call echoed the main points made during the initial call between Obama and Abbott on Friday afternoon.

Obama, speaking from the South Lawn of the White House on Monday, said Russian-backed separatists, who are controlling the crash site, need to allow investigators to recover bodies. He said they had previously fired their weapons in the air when investigators approached the scene and have tampered with evidence.

"Russia, and President Putin in particular, has a direct responsibility to compel them to cooperate with the investigation," Obama said.